Improved peocess of extracting the precious metals from ores



A. OTT.

IPRQGESS 0F BXTRAGTING PRBGIDUS METALS PROM GRES.

Patented Mar. 10; 1868.

MMM I. Mm'

Second, if the oro is a silver ore, it is, after being roasted, brought directly in the centrifugal machine of the apparatus B, and treated with hot water returned severaltimes over andiover the same ore, and the liquid resulting from that treatment, holding in solution the silver-salts, is pumped up from the tank Z into the tankT, from whence it drops in a fine shower down the flue S, where the sulphurettedhydrogen produced in the furnace4 A, as already described, will precipitate the silver in the shape of sulphite, the liquid being pumped up again and again from Z to T, until it contains no more i'ree sulphate, or other soluble salts of silver, The precipitate is collected, dried, 'and melted with iron, producing salphuret of iron and pure silver.

Thirdly, if the or'e or tailings contain an alloy of gold and silver, they are, after beingroasted, brought into the tanks Z2 b, &c., where they are steamed and treated for ten or twelve hours in'prescnce of steam with a solution of double sulphite of an alkali or earthy base, or with a hyposulphite of :in alkaline, earthy, or metallic base. The pasty matter resulting from that treatment is brought inptothe centrifugal machine, and the liquid portion treated as described for silver ore, the gold and silver being afterwards separatedby ordinary means. Y Y n In describing my improved process,'-I have mentioned sometreatmen'ts which are often'employed', saturation, precipitation, filtration, 5w., and I'do not claim any of these as new, if accomplished by f\ther chemical agency, or under other circumstances= than. such as I have described in myspecification; but

What I claim as new, and desire to secure by Letters Patent-ofthe United States, isf-- 1. Roasting snlphurets, tailings, andresidua from other treatments, either alone er mixed Vwith chemicals, in the progressive and continuous manner herein described.

2. In the roastingprocess of the ore-or tailings, the' use-of chloride of iron, copper, or magnesium,-and of hypochloritesrof an alkaline, earthy, or metallic base, mixed with the ore or tailings, and employed as specified.

3. The introduction of hyponitrousacid ges, or oxygen gas, obtained as set forth, in' the roasting process.

4. `precipitating precious metals from asolution of their soluble salts by 'means and with the use of the sniphuretted hydrogen gas produced in the process of roasting said ore, or by a solution of the same -in water.

l 5. The extraction of silver, or of silverand gold, from the roasted ore, .by means and with 'the use of the double sulphite of an alkaline base, (KO 2502, or NaO, 2S 02,) andof-the hyposulphites of-an earthy or metallic base, inthe manner specified.

ADOLPH OTT. [SEAL] Witnesses:

Gnonen SIMON, A. L. HENRY, 

